This invention relates to electro-optical data reading devices, and more specifically, to a device for illuminating bar codes on a record surface and transmitting reflected light to a sensory device.
Data entry systems for direct entry to a processing system from a record member without a man-machine interface are well known in the prior art. Card readers, magnetic tape devices and disk files are a few of these applications. However, these are frequently quite expensive and more suited to high volume data processing. Another direct data entry system which is more apt to be suited to mechandising, inventory, and point of sale operations includes a sensor which may be stationary or mobile, for example, hand-held. A bar-code record is moved past the sensor, or in the case of the hand-held application, the sensor is moved across the record. The data is converted by a light-sensitive device to electrical signals, then processed.
To perform this operation, most systems employ an LED illumination source, and a means for transmitting the differing reflected light levels of the code bars and the record medium, usually a fiber-optic bundle, to a light-sensory means. A problem with this type of reader device has been two-fold. First, for the applications previously mentioned, the possibility of large numbers of these readers being required by a user makes low price a prime consideration. Historically, fiber optics bundles are expensive, and sometimes not easily adapted to this type use. Secondly, the fiber optic bundles have been fairly fragile, and quite susceptible to frequent damage in the environment where they would be used.
Other hand-held code readers include an LED and a sensor usually mounted in a housing of metal or plastic. U.S. Pat. Nos. 3,784,794 and 3,892,973 are made up of these components. Each requires a spherical object at the tip of the assembly for conducting light to the record medium, and conducting light reflected from the record medium to a sensor. The sensor converts the light to electrical signals, which are processed by a digital computer. These readers require complicated assembly procedures and exact positioning of elements, adding to the cost of the special parts. Also, mounting of the parts in semi-rigid housing will subject these parts to high levels of shock when exposed to abuse.
It is therefore an object of the present invention to provide an illuminator-light transfer device which is very inexpensive. Another object of this invention is to provide a device, suited for use in a bar code reader, which will be rugged and impervious to environmental extremes.